Graphic analytic: four typical LED light distribution curve

The first kind of rectangular LED

mainly used for electrical appliances or the indicator lights on the instrument, luminous intensity is very low. Figure 2 is a 45 ° and the spacing between the green LED to a total of eight profile of light distribution curve. Although the shape of their dissimilarity, but the same method to the luminous intensity, is 216 MCD, as can be seen from the diagram, only in the near normal direction of the light distribution curve shape is the same. Just think if there is no article 8 of the light distribution curve, as shown by law to the luminous intensity values, will think it is a good pipe.

the second oval LED

this is a recent products, mainly used for display. Around because of the Angle of display requirements, and the fluctuation is small, so that is suitable for people's visual characteristics. So the oval LED long axis view Angle is large, the short axis view Angle is small, as shown in figure 3 ( a) And ( b) Shown below. In the installation position of display screen is the axis of the tube along the horizontal direction, short axis is perpendicular to the direction.

the third traffic light special LED

road traffic signal lamp although color is divided into three red, green, yellow, but their light distribution curve shape is as shown in figure 4. Unlike other LED, its flood light distribution curve, has the serious asymmetry. This makes sense, because of traffic light looking both motor vehicle drivers, cyclists and passers-by, eyes are far below the traffic lights, if use common monochrome leds, exposure to the sky light is useless, on electricity caused great waste.

the fourth kind of monochromatic light LED

quite a proportion of monochromatic light LED light distribution curve as shown in figure 5, the luminous intensity distribution of the surrounding big middle small. If a piece of white paper, will present a bright ring around it and the middle is the image of dark spots. At the beginning of its slightly, see figure 6: on the one hand, because the appearance of the LED equivalent of a lens, but it is not an ideal lens. , on the other hand, although common LED chip area is 011 ~ 0125 was only, but in terms of relative lens chip light-emitting viewing Angle is large, so the chip cannot be regarded as a point source. Different field of light gather near A point spread out again on A circle, near the far field caused by the outside light appeared the phenomenon of bright in the dark.

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